This is a non-randomized study to estimate the frequency of eradication of MAC in previously MAC-infected individual with an adequate response to antiretroviral therapy. If subjects' CD4+ lymphocyte counts decrease to <50 cells/mm3 , MAC treatment will be reinstituted. The primary objective is to determine if anti-mycobacterial therapy can be withdrawn from subjects who have received 12 months of macrolide-based therapy, are asymptomatic for MAC for at least 16 weeks, have CD4 counts>100 and are on antiretroviral therapy for 16 weeks; and to estimate the duration of time these subjects remain free of MAC infection.